Prevalence and Implications of Abnormal Laboratory Results in Patients in the Terminal Phase of Life

Transformation of Sequential Hospital and Outpatient Laboratory Data into Between-Day Reference Change Values

BACKGROUND

Serial differences between intrapatient consecutive measurements can be transformed into Taylor series of variation vs time with the intersection at time = 0 (y0) equal to the total variation (analytical + biological + preanalytical). With small preanalytical variation, y0, expressed as a percentage of the mean, is equal to the variable component of the reference change value (RCV) calculation: (CVA2 + CVI2)1/2.

METHODS

We determined the between-day RCV of patient data for 17 analytes and compared them to healthy participants' RCVs. We analyzed 653 consecutive days of Dartmouth-Hitchcock Roche Modular general chemistry data (4.2 million results: 60% inpatient, 40% outpatient). The serial patient values of 17 analytes were transformed into 95% 2-sided RCV (RCVAlternate), and 3 sets of RCVhealthy were calculated from 3 Roche Modular analyzers' quality control summaries and CVI derived from biological variation (BV) studies using healthy participants.

RESULTS

The RCVAlternate values are similar to RCVhealthy derived from known components of variation. For sodium, chloride, bicarbonate calcium, magnesium, phosphate, alanine aminotransferase, albumin, and total protein, the RCVs are equivalent. As expected, increased variation was found for glucose, aspartate aminotransferase, creatinine, and potassium. Direct bilirubin and urea demonstrated lower variation.

CONCLUSIONS

Our RCVAlternate values integrate known and unknown components of analytic, biologic, and preanalytic variation, and depict the variations observed by clinical teams that make medical decisions based on the test values. The RCVAlternate values are similar to the RCVhealthy values derived from known components of variation and suggest further studies to better understand the results being generated on actual patients tested in typical laboratory environments.

Vancomycin Pharmacokinetics in Patients with Advanced Cancer Near End of Life

BACKGROUND AND OBJECTIVE

The effect of cancer cachexia on the pharmacokinetics of vancomycin remains unclear. We investigated whether the pharmacokinetics of vancomycin and the risk of kidney injury are altered with the development of cancer cachexia.

METHODS

A retrospective analysis was conducted using therapeutic drug monitoring data obtained from 86 cancer patients who received vancomycin intravenously for infection. The patients were classified into four groups according to the stage of cachexia defined by international consensus-non-cachexia (n = 26), pre-cachexia (n = 10), cachexia (n = 21) and refractory cachexia (n = 29). Vancomycin pharmacokinetics were analyzed by a traditional one-compartment model and Bayesian method using plasma concentrations measured in these patients. Renal function and pharmacokinetic parameters were compared between the non-cachexia patients (n = 26) and total cancer cachexia patients (n = 60).

RESULT

No significant difference in estimated glomerular filtration rate was observed between the non-cachexia and the total cancer cachexia patients. In contrast, systemic clearance of vancomycin was significantly lower in the total cancer cachexia patients compared with the non-cachexia patients when analyzed by the traditional one-compartment model [median (range)-49.7 (9.8‒98.7) vs 70.2 (12.5‒211.8) mL/min, p < 0.01] and by the Bayesian method [45.6 (12.5-84.7) vs 63.3 (12.2-102.5) mL/min, p < 0.05]. None of the non-cachexia patients developed kidney injury, whereas 15% (9 of 60 patients) of the total cancer cachexia patients developed kidney injuries (p = 0.052).

CONCLUSIONS

The present study revealed that cancer patients with cachexia may have reduced vancomycin clearance compared with those without cachexia. Cancer cachexia may be a risk factor of vancomycin-associated kidney injury, independent of renal function.

Amikacin Pharmacokinetics in Terminal Stage of Hematological Malignancy

BACKGROUND

The influence of cancer cachexia on the pharmacokinetics of and kidney injury caused by amikacin remains unclear. This study investigated whether the pharmacokinetics of amikacin and the risk of kidney injury are altered with the progression of cancer cachexia.

METHODS

A retrospective analysis was conducted using therapeutic drug monitoring data obtained from 52 cancer patients who received amikacin intravenously for infection(s). The patients were classified into 2 groups based on the status of cachexia using a consensus definition: noncachexia group (n = 31) and cachexia group (n = 21). Differences in amikacin pharmacokinetics and occurrence of kidney injury were compared between the 2 groups. Amikacin pharmacokinetics was calculated based on a 1-compartment model using peak and trough concentrations measured clinically for therapeutic drug monitoring. In addition, intrapatient analysis was conducted based on patients who received amikacin treatments more than once during the study period to examine the alteration in amikacin pharmacokinetics with the progression of cancer cachexia.

RESULTS

Systemic clearance of amikacin [median (range)] was significantly (P < 0.05) lower in the cachexia group [37.3 (11.2-87.3) (mL/min)] than in the noncachexia group [52.0 (19.1-133.4) (mL/min)]. In contrast, volume of distribution was significantly (P < 0.05) increased in the cachexia group [0.47 (0.20-1.45) L/kg] compared with the noncachexia group [0.32 (0.21-1.00) L/kg]. There was no difference in the occurrence of kidney injuries between the 2 groups. In an intrapatient analysis of the longitudinal alteration of amikacin pharmacokinetics, an approximately 50% reduction in clearance and 30% increase in volume of distribution were observed as cancer cachexia progressed.

CONCLUSIONS

The present study suggests that progression of cancer cachexia may reduce amikacin clearance and increase the volume of distribution, but cancer cachexia does not increase amikacin-induced kidney injury.

Factors Associated with the Effectiveness of Intravenous Administration of Chlorpromazine for Delirium in Patients with Terminal Cancer

BACKGROUND

Delirium in patients with terminal cancer is irreversible and increases treatment resistance, which leads to a deterioration in quality of life.

OBJECTIVE

To investigate factors affecting the effectiveness and safety of intravenous chlorpromazine for irreversible delirium in patients with terminal cancer.

DESIGN/MEASUREMENTS

Multiple regression analysis for factors affecting treatment effectiveness was carried out based on a retrospective comparison between responders and nonresponders to intravenous chlorpromazine.

SETTING/SUBJECTS

Ninety-seven patients with terminal cancer who were treated with intravenous chlorpromazine for irreversible delirium were included.

RESULTS

The rate of patients with ≥50% improvement in mean Nursing Delirium Screening Scale score from pretreatment to day three of chlorpromazine treatment was 0.48 (95% confidence interval [CI]: 0.38-0.58). Factors affecting chlorpromazine treatment effectiveness were hyperactive delirium (odds ratio [OR]: 6.25, 95% CI: 1.14-34.5) and longer survival (OR: 1.096, 95% CI: 1.05-1.14). The mean chlorpromazine dose was low, at 17.9 mg/day. Adverse events were reported in 11 patients (11.3%) by day three of chlorpromazine treatment, and all were observed in patients who survived less than two weeks after chlorpromazine treatment. Patients who died, who had decreased blood pressure during chlorpromazine administration, and who showed acute akathisia all displayed shock index ≥1.

CONCLUSIONS

Intravenous administration of low-dose chlorpromazine may be an effective and safe treatment option for delirium in patients with terminal cancer who have hyperactive delirium, longer predictive prognosis, and shock index <1.

Use of parecoxib by continuous subcutaneous infusion for cancer pain in a hospice population

OBJECTIVES

To characterise the use of the parenteral non-steroidal anti-inflammatory drug parecoxib when given by continuous subcutaneous infusion (CSCI) in a hospice population. Clinical experience suggests parecoxib CSCI may be of benefit in this population, but empirical evidence in relation to its safety and efficacy is lacking.

METHODS

Retrospective chart review of patients with a cancer diagnosis receiving parecoxib CSCI from 2008 to 2013 at the Marie Curie Hospice, Belfast. Data were collected on treatment regime, tolerability and, in patients receiving at least 7 days treatment, baseline opioid dose and changes in pain scores or opioid rescue medication requirements.

RESULTS

Parecoxib CSCI was initiated in 80 patients with a mean administration of 17.9 days (median 11, range 1-94). When used for a period of 7 days, there was a statistically significant reduction in pain scores (p=0.002) and in the number of rescue opioid doses required (p=0.001), but no statistically significant opioid-sparing effect (p=0.222). It was generally well tolerated, although gastrointestinal, renal adverse effects and local site irritation were reported.

CONCLUSIONS

Parecoxib may have a valuable place in the management of cancer pain, especially towards the end of life when oral administration is no longer possible and CSCI administration is relied on. Further studies into the efficacy and tolerability of parecoxib CSCI are merited.